Saturday, May 28, 2011

You take 20 images and you find this in the 20th image and it wasn't in the 19th and of course there was no image 21.

Fast moving objects are nearly impossible to measure (in this case don't know which way it was going). You can try cutting it in two with pixel math and taking three points with timings as the start, midpoint and end of the image - but that assumes you know which way it was going.

In this 30 sec image it has moved about 200 Pixels.

Always a possibility it is a satellite but the speed and angle do look ok for a close approaching asteroid.

Thursday, May 26, 2011

Its been a little while since I have chased asteroids, but with the new Focal reducer I thought I'd put in some time as there were 60 confirmations up on the MPC Confirmation page.

I was looking for something around Mag 21 to test the scope out now its F/4.4.

P100ZPJ looked like a good target as it was pretty high in the sky and the last couple of frames I lost as they were moon affected. I did manage to stack 6x300 sec subs into this fine shot. Residuals were good and its between mag 20 and 21. Offically it was supposed to be Mag 21.2 but Spacewatch II got it at mag 20.5 as well at about the same time.

Monday, May 16, 2011

Update 23/5/2011The moon is now wanning and I have re-visited Elenin on the 23rd to see how it is after the moon has passed through. This color composite image is stacked once to create a star layer, and again for movement of the comet, to get the coma nice and tight. The two layers are combined in photoshop with a feathered cutout in the star layer revealing the Comet layer behind. This is the quick and easy way of good color comet photos, given the comet is still pretty faint. The image is a one hour of RGB in 300sec subs, processed in Maxim DL (stack & combine) and Photoshop(curves and layers). If you look carefully you will see Elenin passing a tiny little distant Galaxy.Enjoy!

Original Post.The full moon is not the best time to be imaging comets - but what the hell! I had a focal reducer fitted to the planewave this week taking it down to F/4.4 so I had to shoot something to try it out.

Here is the latest image of comet Elenin, May 16th at 2011-05-16 03:54:21 UTC, this time in color. I was processing the images and noticed a couple of asteroids very close which certainly made it a worthwhile exercise, even if the images were a bit noisy from the full moon.

This image is 5 x 300 secs of each color R/G/B color combined. Each image tracked the movement of Elenin, thus trailing the background stars slightly in each color.

Passing in the opposite directions across the plate are Asteroid Zoya (1793) at Mag 15.9 and (7503)1996 VJ38 which appears to have "crossed" the (apparent) path of Elenin perhaps about 8-10 hours before my images photos were taken.

Also when the moon is bouncing around it will often give extra highlights to dust donuts that flats normally remove when its nice and dark.